QO The Animal Mind 



smell of food or larvae about an ant returning laden to the 

 nest is a stimulus to her nestmates to follow her; that this 

 smell is stronger, the larger the stock she has found, and 

 hence acts as a more powerful stimulus. 



27. How Ants find the Way Home 



Lubbock's experiments indicated also that in finding their 

 way back to the nest ants make more use of smell than of sight. 

 One only of these observations need be described. Lub- 

 bock placed larvae in a dish on a table connected by a bridge 

 with an ant nest. He accustomed the ants to go back and 

 forth from the dish to the nest along a path which he diversi- 

 fied by artificial scenery, such as rows of bricks along either 

 side, and a paper tunnel. When the- path was thoroughly 

 learned he moved the bricks and the tunnel so that they led 

 in a different direction; the ants, however, were not at all 

 disconcerted by this cataclysm of nature, but followed the 

 same track as before, evidently guided by their own footprints 

 (248, p. 259). The direction of the light is not without some 

 influence, however. When two candles that had stood near 

 the nest were moved to the opposite side, some of the ants 

 were confused (248, p. 268). Bethe, whose object is to show 

 that all ant behavior is a series of unconscious reflexes to 

 chemical stimuli, made the following attempt to study the 

 formation of a new ant path. He placed near the entrance 

 to a nest a large sheet of paper covered with lampblack, on 

 which the footsteps of the ants could be traced. On this paper 

 he placed a supply of food. When an ant had found the food, 

 in going back to the nest she always followed the path by 

 which she had come, except that when the original path had 

 crossed itself in loops, the ant omitted the loops in returning. 

 Other ants followed the same path, though they all had a ten- 

 dency to cut off curves (30). Wasmann, the ardent opponent 



